Cannot use send later when Outlook DLP add-in for Mac is installed

Products

• Data Loss Prevention Endpoint Prevent
• Data Loss Prevention
• Data Loss Prevention Endpoint Discover
• Data Loss Prevention Endpoint Suite
• Data Loss Prevention Network Email
• Data Loss Prevention Network Monitor and Prevent for Email
• Data Loss Prevention Network Prevent for Email
• Data Loss Prevention Plus Suite

Issue/Introduction

You have deployed the DLP Add-in for Outlook on the Mac OS via the Microsoft Admin Center for Office 365

Since then you've noticed that some functionality in Outlook is impaired for example:

• The Send button is disabled when Outlook is in offline mode
• The 'Send Later' option is not available

Environment

Release : 15.7, 15.8

Component : Outlook Add-in for Mac OS

Cause

Various

Resolution

There are some known limitations to the OnSend Addin types, generally. Please note the points below.

Platforms:

• The Outlook Addin is required for DLP detection on Mac OS 11.x or greater
• Windows machines do not need this add-in, they use a COM add-in for Outlook which is applied during agent installation

Limitations

The majority of the limitations below apply to all 'On-Send' type of add-ins in Outlook, not just the Symantec DLP one.

• It only works for Office 365 subscription.
• Send Later feature is not available with onSend add-ins
• Only one ItemSend event is supported per add-in.
• OnSend Add-in is not available for group mailboxes.
• OnSend Add-ins cannot be published to AppSource.
• OnSend Add-ins does support Outlook in Offline mode
• OnSend requires API requirement set 1.8 of Office Javascript. So, Outlook for Mac version 16.30+ which supports it.
• OnSend does not work with mail marked 'Do Not Forward' and 'Encrypt Only' options
• OnSend does not work with AIP Encrypted Emails generated by selecting below Encrypt options:
  • Confidential \ All Employees
  • Highly Confidential \ All Employees

See Microsoft article (external) for additional details